Within the last decades, the framework of stochastic thermodynamics
(ST) [1]}, [2]}, [3]} has
been established as a powerful tool to analyse the dynamical and
thermodynamic properties of small, mesoscopic systems out of
equilibrium
[4]}, [5]}, [6]}, [7]}.
Paradigmatic examples whose thermodynamic fluctuation properties
have been studied experimentally are driven colloidal particles
[8]}, biopolymers [9]}, and molecular
Szilard-type engines [10]}. But concepts of ST are
nowadays also used for open quantum systems
[11]}, [12]}, nonlinear electronic
circuits [13]}, electron shuttles
[14]}, and open, coarse-grained systems
[15]}. In these mesoscopic systems, observables
of interest like the position of a particle typically fluctuate
strongly due to interactions with an environment. The key step of ST
is to define thermodynamic quantities such as heat, work and entropy
along single fluctuating trajectories [1]}, [2]}, allowing one to investigate not only
ensemble averages as in the (phenomenological) thermodynamics of
large, macroscopic systems, but also fluctuations of these quantities.
